Small beginnings: Interactions between fire timing and the giant sequoia seedling generation niche

Abstract Background: As fire regimes change under a warming climate, ideal tree seedling recruitment locations and conditions are important to understand for forest management and restoration. In forests adapted to frequent, low-intensity fire, reintroduction of fire is often the preferred or recommended management approach. Little work, however, has explored the interacting roles of local-scale microhabitat and fire severity in determining post-fire recruitment. Here we use a back burn applied to a giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz) grove in Yosemite National Park, California, to ask how sub-meter microhabitat variation influences seedling establishment and growth following fire. Results Post-fire S. giganteum seedling establishment was greatest in microhabitats with lower burn severity, higher post-fire sequoia litter, higher moss cover, and higher presence of sequoia cones. Conclusion These results indicate the importance of burn severity coupled with propagule pressure and post-fire surface organic matter in defining the seedling regeneration niche. These attributes should be incorporated in future fire management and seedling recruitment plans.